This invention relates to rotating machines.
Superconducting air-core, synchronous electric machines have been under development since the early 1960""s. The use of superconducting windings in these machines has resulted in a significant increase in the field electromotive forces generated by the windings and increased flux and power densities of the machines.
Early superconducting machines included field windings wound with low temperature superconductor (LTS) materials, such as NbZr or NbTi and later with Nb3Sn. The field windings were cooled with liquid helium from a stationary liquifier. The liquid helium was transferred into the rotor of the machine and then vaporized to use both the latent and sensible heat of the fluid to cool the windings. This approach proved to be viable for only very large synchronous machines. With the advent of high temperature superconductor (HTS) materials in the 1980""s, the cooling requirements of these machines were greatly reduced and smaller superconducting machines were realizable.
While HTS materials reduce the cooling requirements of superconducting machines, it is still important that the field windings of these machines remain sufficiently cool so that they maintain their superconducting characteristics and properties. Accordingly, these machines utilize various assemblies that thermally insulate these cool field windings from the warm output shaft of the machine.
According to an aspect of this invention, a superconducting rotor assembly includes an axial shaft. A torque tube is connected to a winding support structure. An interconnection assembly mechanically couples the torque tube to the axial shaft. This interconnection assembly is configured to convert a torsional torque load experienced by the torque tube to a tangential torque load which is provided to the axial shaft.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The thermally-insulating interconnection assembly includes a torque tube flange for connecting the interconnection assembly to the torque tube. An axial flange connects the interconnection assembly to the axial shaft and at least one thermally-insulating tangential load-bearing member connects the torque tube flange to the axial flange. The axial flange may also be a collar. Further, the axial flange may be directly connected to one of the end plates connected to the axial shaft of the rotor assembly.
The torque tube flange includes at least one protruding bracket assembly positioned radially about the torque tube flange. The protruding bracket assemblies are configured to connect the torque tube flange to the thermally-insulating tangential load-bearing members.
The axial flange includes at least one protruding bracket assembly positioned radially about the axial flange. The protruding bracket assemblies are configured to connect the axial flange to the thermally-insulating tangential load-bearing members.
The thermally-insulating tangential load bearing members are constructed of a high-strength, low thermal conductivity composite material, such as a G-10 phenolic material. The torque tube is constructed of a high-strength, low thermal conductivity metallic material, such as Inconel.
A superconducting winding assembly is mounted on the winding support structure. The superconducting winding assemblies are constructed using a high-temperature superconducting material. The high temperature superconducting material is chosen from the group consisting of: thallium-barium-calcium-copper-oxide; bismuth-strontium-calcium-copper-oxide; mercury-barium-calcium-copper-oxide; and yttrium-barium-copper-oxide. The superconducting rotor assembly further includes a refrigeration system for cooling the superconducting winding assembly.
According to a further aspect of this invention, an interconnection assembly for converting a torsional torque load experienced by a torque tube to a tangential torque load which is provided to an axial shaft includes a torque tube flange for connecting the interconnection assembly to the torque tube. An axial flange connects the interconnection assembly to the axial shaft. At least one thermally-insulating tangential load-bearing member connects the torque tube flange and the axial flange.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The axial flange may be a collar or may be directly connected to one of the end plates connected to the axial shaft of the rotor assembly.
The torque tube flange includes at least one protruding bracket assembly positioned radially about the torque tube flange. The protruding bracket assemblies are configured to connect the torque tube flange to the thermally-insulating tangential load-bearing members.
The axial flange includes at least one protruding bracket assembly positioned radially about the axial flange. The protruding bracket assemblies are configured to connect the axial flange to the thermally-insulating tangential load-bearing members. The thermally-insulating tangential load bearing members are constructed of a high-strength low thermal conductivity composite material, such as a G-10 phenolic material. The torque tube is constructed of a high-strength, low thermal conductivity metallic material, such as Inconel.
According to a further aspect of this invention, a superconducting rotor assembly includes an axial shaft and a winding support structure. An asynchronous field filtering shield surrounds the winding support structure. The asynchronous field filtering shield is connected to the axial shaft via one or more end plates positioned on distal ends of the shield. An interconnection assembly connects the winding support structure to the asynchronous field filtering shield. The interconnection assembly is configured to convert a torsional torque load experienced by the winding support structure to a tangential torque load which is provided to the asynchronous field filtering shield.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The thermally-insulating interconnection assembly includes one or more discrete torque transfer assemblies. Each discrete torque transfer assembly includes at least one support structure bracket assembly rigidly attached to the winding support structure, and at least one shield bracket assembly rigidly attached to the asynchronous field filtering shield and positioned proximate the at least one support structure bracket assembly. At least one thermally-insulating tangential load-bearing member, which is positioned between the at least one support structure bracket assembly and the at least one shield bracket assembly, connects the at least one support structure bracket assembly and the at least one shield bracket assembly. The at least one thermally-insulating tangential load bearing member is constructed of a high-strength low thermal conductivity composite material, such as a G-10 phenolic material. The at least one shield bracket assembly and the at least one support structure bracket assembly are constructed of a high-strength, low thermal conductivity metallic material, such as Inconel. A superconducting winding assembly is mounted on the winding support structure. The superconducting winding assembly is constructed using a high-temperature superconducting material. The superconducting rotor assembly includes a refrigeration system for cooling the superconducting winding assembly.
According to a further aspect of this invention, an interconnection assembly for converting a torsional torque load experienced by a winding support structure to a tangential torque load which is provided to an asynchronous field filtering shield includes one or more discrete torque transfer assemblies. Each discrete torque transfer assembly includes at least one support structure bracket assembly rigidly attached to the winding support structure, and at least one shield bracket assembly rigidly attached to the asynchronous field filtering shield and positioned proximate the at least one support structure bracket assembly. At least one thermally-insulating tangential load-bearing member, which is positioned between the at least one support structure bracket assembly and the at least one shield bracket assembly, connects the at least one support structure bracket assembly and the at least one shield bracket assembly.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The at least one thermally-insulating tangential load bearing member is constructed of a high-strength low thermal conductivity composite material, such as a G-10 phenolic material. The at least one shield bracket assembly and the at least one support structure bracket assembly are constructed of a high-strength, low thermal conductivity metallic material, such as Inconel.
According to a further aspect of this invention, a superconducting rotor assembly includes an axial shaft and a winding support structure. At least one end plate is rigidly attached to the axial shaft at a distal end of the winding support structure. An interconnection assembly connects the winding support structure to the at least one end plate. The interconnection assembly is configured to convert a torsional torque load experienced by the winding support structure to a tangential torque load which is provided to the at least one end plate.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The thermally-insulating interconnection assembly includes one or more discrete torque transfer assemblies. Each discrete torque transfer assembly includes at least one support structure bracket assembly rigidly attached to the winding support structure, and at least one end plate bracket assembly rigidly attached to the at least one end plate and positioned proximate the at least one support structure bracket assembly. At least one thermally-insulating tangential load-bearing member, which is positioned between the at least one support structure bracket assembly and the at least one end plate bracket assembly, connects the at least one support structure bracket assembly and the at least one end plate bracket assembly. The at least one thermally-insulating tangential load bearing member is constructed of a high-strength low thermal conductivity composite material, such as a G-10 phenolic material. The at least one end plate bracket assembly and the at least one support structure bracket assembly are constructed of a high-strength, low thermal conductivity metallic material, such as Inconel. A superconducting winding assembly is mounted on the winding support structure. The superconducting winding assembly is constructed using a high-temperature superconducting material. The superconducting rotor assembly includes a refrigeration system for cooling the superconducting winding assembly.
According to a further aspect of this invention, an interconnection assembly for converting a torsional torque load experienced by a winding support structure to a tangential torque load which is provided to at least one end plate includes one or more discrete torque transfer assemblies. Each discrete torque transfer assembly includes at least one support structure bracket assembly rigidly attached to the winding support structure, and at least one end plate bracket assembly rigidly attached to the at least one end plate and positioned proximate the at least one support structure bracket assembly. At least one thermally-insulating tangential load-bearing member, which is positioned between the at least one support structure bracket assembly and the at least one end plate bracket assembly, connects the at least one support structure bracket assembly and the at least one end plate bracket assembly.
Embodiments of this aspect of the invention may also include the following. The interconnection assembly is configured to receive a tangential torque load which is a compression load or a tension load. The at least one thermally-insulating tangential load bearing member is constructed of a high-strength low thermal conductivity composite material, such as a G-10 phenolic material. The at least one end plate bracket assembly and the at least one support structure bracket assembly are constructed of a high-strength, low thermal conductivity metallic material, such as Inconel.
One or more advantages can be provided from the above aspects of the invention. The cool rotor winding can be thermally insulated from the warm output shaft of the rotating machine. This can be accomplished while providing a high-strength connection between the rotor windings and the output shaft. The strength of the torque tube can be increased by constructing it from a high-strength, moderately thermally insulating material. By constructing the tangential load bearing members from a moderately strong, highly thermally insulating material, the cool rotor windings can be thermally isolated from the warm output shaft. Additionally, by positioning the tangential load bearing members so that they are only exposed to compressive loading, any strength-related shortcomings associated with the moderately strong, highly thermally insulating material can be minimized.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.